Small wonders

From possible to potential, nanomedicines have successfully managed to establish their identity. Moreover, their impact on modern medicines and healthcare is going to be monumental. Sachin Jagdale analyses

Imagine a small capsule measuring in nano metres, scanning your internal organs and providing details to censors placed outside. This may have sounded like science fiction a couple of years ago, but today, imagination has transformed into reality. It's been a collaboration between medicine and nanotechnology that has given birth to the revolutionary concept of nanomedicine, which is the medical application of nanotechnology. Nano-sized particles have been considered and investigated as potential medicines for many decades.

Over the years scientists have been studying the structures of small molecules and using them to produce biologically active materials. There are different forms of materials that could be considered as nanomedicine, for example, polymers, liposomes, emulsions, nano particles, proteins etc. New hybrid nanomaterials can be used to produce a highly efficient MRI contrast.

Why nanomedicines?

"Nanomedicine will improve the efficacy of the drugs, help target the drug specifically to the desired area thus minimise unnecessary side effects and toxicity" - Dattatri K Nagesha Research Co-ordinator, IGERT Nanomedicine Science and Technology program, Associate Research Scientist, Department of Physics Northeastern University, Boston

In the coming years nanomedicine is going to provide genuine research and clinically helpful devices. Today, nanomedicine is among the fastest growing industries on the international arena. Nanomedicine sales from more than 200 companies all over the world clocked $6.8 billion in 2004. Investments in nanotechnology and R&D amount to around $3.8 billion every year.

Many conventional medicines result in side effects as some of them are not as target oriented as desired. This problem can be solved using the bioavailability property of nanoparticles so that drugs can act directly on the desired organ or portion of the organ. Dattatri K Nagesha, Research Co-ordinator, Integrative Graduate Education and Research Traineeship (IGERT), Nanomedicine Science and Technology program, Associate Research Scientist, Department of Physics Northeastern University, Boston, says, "In nanomedicine, nanotechnology is not going to create new drugs but rather enable new ways to deliver the existing drugs. For example, Paclitaxel is a poorly soluble chemotherapeutic drug and is limited in its potential use due to this. But by encapsulating this drug within either a biodegradable polymer or liposome matrix, the problem with solubility can be overcome and delivered to tumour site." He adds further, "Nanomedicine will therefore improve the efficacy of the drugs, help target the drug specifically to the desired area thus minimising unnecessary side effects and toxicity. Overall, nano-medicine will help improve quality of life."

"With nanomedicines I am able to deliver a drug directed against a tumor using a vehicle (medium). Unnecessary intravenous (IV) lines and related complications can be prevented" - Dr Shishir Shetty, Surgical Oncologist, Wockhardt Hospitals

Thus the unusual properties of nano particles can be used for more efficient drug delivery. While sighting the importance of this property Dr Shishir Shetty, Surgical Oncologist, Wockhardt Hospitals says, "It is a wonderful concept. With nanomedicines I am able to deliver a drug directed against a tumor using a vehicle (medium). Unnecessary intravenous (IV) lines and related complications can be prevented. I may be able to give very small amounts of chemotherapy to destroy tumour."

Innovative moves

As the human body discharges larger particles, cells can take up the nanoparticles because of their smaller size. Improved behavior and specific mechanism have made nanoscience and nanomedicine an integral part of modern medicine. Scientists have come up with a photodynamic therapy where a nanoparticle is illuminated with light from the outside. In case the particle is a metal it will become hot and destroy the desired tissue without affecting normal tissues/cells and leaving no toxic residues. Another interesting concept associated with nanomedicines that will revolutionise the medical field is nano robots. These nano robots can flow through the circulatory system and detect defective cells. Again, this will revolutionise cancer treatment. Scientists are working towards designing nanodevices that can be connected to the nervous system. If they are successful, it will allow them to monitor impulses using a computer.

Crafting dreams

With each passing day the world of nanomedicine is becoming smaller and smaller. If Hippocrates, the father of modern medicines was here, he would have been more than happy seeing the transformation of medicines he discovered. Curious researchers, possessed with intelligent tools and techniques, are all set to change virtually every facet of modern medicines. Almost all major pharma companies and research institutions have ongoing projects on nanomedicine research.

"One of the most important aspects of nanomedicine has been in early diagnostics," says Dattatri. "Semi-conductor nanoparticles, also known as quantum dots, have excellent optical properties and being used to detect early stages of cancer. This technology has tremendous promise and has not reached its full potential yet. Using magnetic resonance imaging (MRI), early stages of cancer is detected with the help of iron oxide nanoparticles as contrast enhancing agents."

Dr Jayesh Bellare, Professor, Department of Chemical Engineering, and School of Biosciences and Bioengineering, IIT Bombay, lists other aspects of research. He cites, "Synthetic bone carrying factors and drugs, anti-microbials, nanoparticles for drugs via nasal, oral and ophthalmic routes, nanoaerosols, microcantilevers and biomedical devices these are some of the areas of research where principles of nanomedicines are being applied." He adds, "A unique field is that of traditional medicines and even homeopathy, where we are looking at the mode of action from a modern scientific viewpoint using tools of nanotechnology. Neutraceuticals is another important field allied to medicine where bio and nanotechnology is being worked on."

Still suspicious

Though nanomedicine is attracting a fair amount of praise for its effectiveness, there are some hitches as well. Nanoparticles like non-biodegradable polystyrene nanospheres with small diameters have been known to cause pulmonary inflammation. Besides this, many nanoparticles are still on trial and their effectiveness and long term effects are still to be ascertained.

"Any new technology has its share of drawbacks. One of the challenges with nanotechnology and nanoscience is that it is a new science. A lot about the properties is not known yet. For example, what are the long term effects (10-15 years) of using nanotechnology enabled products? The answer to this is not known," cautions Dattatri.

Though the concept of nanomedicines has been around for many decades, it has picked up pace only in the last few years. It is necessary to build awareness among the medical fraternity about latest developments in this field. If this does not happen, then it will be the patient who will be deprived of the miracle of nanomedicines. Dattatri states, "Many a time, doctors treating patients are not aware of the potential benefits of nanomedicines. The advantages of nanomedicine discovered in laboratory research have not been successfully translated as knowledge to the practicing doctors. This is a major hurdle in implementing nanomedicine in a much more elaborate manner." According to Dr Shetty, nanomedicines and nanotechnology are still in infancy in India however tall the claims may be.

Raring to go

Nanomedicine is a scientific miracle, not to entertain but to sustain human life. Nanomedicines have already started doing their noble job and we expect more out of it. As expectations mount, the growth of nanomedicines is also taking a bigger leap. "This enabling technology will have a significant impact in the way we diagnose and treat (illness). Through better formulation, we can decrease the concentration of drugs needed and hence minimise toxic side effects. We are moving forward to a future where instead of generalised treatment option, we will have personalised medical treatment depending on the characteristics of an individual," opines Dattatri. Nano-medicines have provided a new dimension to pharma and healthcare sectors and if Bellare is to be believed, its effect on public health will surpass any previous applications from this sunrise discipline.

sachin.jagdale@expressindia.com